In such an article transport facility, since the movable bodies may collide with each other if the movable bodies are allowed to travel from both the first path and the second path into the merging portion, the movable bodies need to be caused to travel into the merging portion while preventing a collision between the movable body that merge into the merging portion from the first path and the movable body that merges into the merging portion from the second path.
To this end, in a conventional article transport facility, a first merging detecting sensor is provided for detecting whether there is any movable body entering a first merging path that extends from the first path to the merging portion. By communicating the detected information from the first merging detecting sensor to the managing means and by communicating entering information to the managing means from the vehicle that has entered the second merging path extending from the second path to the merging portion, if the managing means determines that there are vehicles that are entering both the first merging path and the second merging path, it issues an operation command information to one of the vehicles to stop its travel to prevent a collision. (See, for example, Patent Document 1.)
In the facility described in Patent Document 1, since the entry of the movable body is detected by the first merging detecting sensor when allowing a movable body entering the first merging path to travel and merge through the first merging path into the merging portion, the managing means issues this first path entering information to the movable body that has entered the second merging path, as operation command information. The managing means continually issues this first path entering information as operation command information until after a predetermined amount time allowed for the movable bodies to complete the merging movements has elapsed. Thus, when a movable body merges into the merging portion through the first merging path, the movable bodies are prevented from colliding with each other by stopping the movable body that has entered the second merging path.
Also, when a movable body enters the second merging path, second path entering information which indicates that the movable body has entered the second merging path is communicated to the managing means. The managing means issues, as operation command information, information obtained by putting together the second path entering information and first entering presence information that indicates whether the first path entering information is detected by the first merging detecting sensor, to each of the movable bodies entering the first and second merging paths. And the managing means continually issues this operation command information obtained by putting together the second path entering information and the first entering presence information until after a predetermined amount time allowed for the movable body to complete the merging travel has elapsed. Thus, if travel controlling means of the movable body that has entered the second merging path determines that a movable body has entered the first merging path based on the first entering presence information, it causes the movable body to stop to prevent a collision between the movable bodies. And if the travel controlling means determines that no movable body has entered the first merging path based on the first entering presence information, it causes the movable body to travel and merge.